Control valve for telemotor type hydraulic power lift



March 18, 1952 J. R. oRELlND ETAL CONTROL VALVE FOR TELEMOTOR TYPE HYDRAULIC POWER LIFT 4 Sheet-s-Sheet 1 Filed Feb. 14, 1947 INV moles.`

March 18, 1952 J. R. QRELINDl ErAL fcoNTRoL VALVE RoR TELEMoToR TYPE: HYDRAULIC RowER LIFT 4 Sheets-Sheet 2 Filed Feb. 14, 1947- BY Cari e/Yg March 18, 1952 Filed Feb. 14, 1947 y'cronrrzoL VALVE FOR TELEMOTOR J R. ORELIND ETAL 2,589,850

TYPE HYDRAULIC POWER LIFT 4 Sheets-Sheet 3 l l: 31a,

March 18, 1952 l J, R, ORELlND ErAL 2,589,850

CONTROL VALVE FOR TELEMOTOR TYPE HYDRAULIC POWER LIFT Filed Feb. 14, 1947 4 snets-sneet 4 Patented Mar. 18, 1952 CONTROL VALVE FOR TELEMOTOR TYPE HYDRAULIC POWER LIFT John R. Orelind, Wilmette, 'and Carl W. Mott,

La Grange,

Ill., assignors to International Harvester Company, a corporation of New Jersey Application February 14, 1947, Serial No. 728,408

13 Claims. 1

vThis invention concerns controls by means of which the plunger of a hydraulic ram is selectively controlled in its movement and more particularly relates to telemeter control of a remotely disposed ram.

One object of the invention is the provision of a control system adapted for operation in conjunction with a remotely disposed hydraulic ram and employing a single control conduit, by means of which fluid pumped in accordance with the direction of operation of the ram is operable to cause the ram to operate in accordance with the amount of movement of a control lever.

A further object is the provision of a hydraulic control system for a hydraulically driven rain and wherein a control member and movable parts of the ram are automatically rephasable.

Another object is the employment of a hydraulic ram control system wherein luid for operating the ram is introduced into the control counterpart of the hydraulic system as an expedient for establishing a rephased condition of a control member and the ram.

Still another object is the provision of a hydraulic ram control system which is operable when containing liquid, and the system being of a character that when it is being initially filled with liquid, this liquid is obtainable from the power circuit for the ram and in a manner expelling air from and lling all voids in the liquid containing portions of the control system.

These and other desirable objects and advantages inherent in and encompassed by the invention will be more fully comprehended upon reading the ensuing description with reference to the annexed drawings, wherein:

Fig. 1 is a side elevational view of a hydraulic ram and control means therefor constructed according to the principles of the invention, the control means for the most part lbeing contained within a casing, of which a side wall portion is broken away and part of the control means Within the casing being shown in section for clarity.

Fig. 2 is a fragmentary view illustrating a hydraulic device of the control mechanism at a limit of operation for opening a foy-pass Valve of such device.

Fig. 3 is a sectional view taken upon a plane extending axially and centrally through the hydraulic ram of Fig. 1.

Fig. 4 is a fragmentary sectional view taken on the line 4 4 of Fig. 1.

Fig. 5 is a horizontal sectional View taken through the apparatus as indicated by the line 5-5 of Fig. 1. y

Fig. 6 is a vertical sectional view taken through a pressure controlling device of the apparatus.

as indicated by the line 6 6 in Fig. 5.

Fig. 7 is an enlarged fragmentary sectional View taken through a side wall of a hollow tractor body and showing an arrangement by means of which operating uid for the hydraulic ram can enter through an opening in the tractor body and also exhaust through such opening, thereby adapting the apparatus for operation in conjunction with a pump mounted externally of the tractor body.

Referring now to the drawings wherein a single preferred embodiment of the invention is illustrated, apparatus contained within a reservoir casing Il, Figs. 1 and 5, is utilized for controlling the position of a piston II'I within a hydrulic ram unit I2. In Figs. 1 and 5 it can be seen that there is a duplication of the control apparatus for another similar ram (not shown), but since the two apparatus are the same the details o1" only one are herein described and corresponding parts of the other apparatus, Where shown, are simply identified by corresponding reference numerals plus the letter a.

The casing ll is adapted for mounting within the hollow body of a tractor (not shown), a side Wall portion of the tractor body being indicated at I3 in Fig. 7. Said casing is adapted to -be inserted upwardly into the tractor body through a bottom opening which is then closed by a plate i4 onvthe bottom of such casing. Fluid from a pump (not shown) driven by the tractor engine and mounted externally of the tractor body is delivered to a control valve l5 in the casing, and this valve is eective for selective introduction of uid into hoses I6 and IT for operating the ram unit I2 which may be mounted either upon the tractor or remotely therefrom.

The valve I5 is settable under control of a manually settable control member I8 which is rockable about an axis a. This member I8 is operably connected with the valve I5 by a hydraulic linkage or assemblage I9 including a hydraulic device 2l in the form of a cylinder 22 containing a piston 23 attached by means of a piston rod 24 and a pivot pin 25 with,l the rockable control member I8. One end of the cylinder 22 is pivotally connected at 26 with a lever 21 pivotally mounted upon a xed pivot member 28. A second xed pivot, 29, provides support for` a lever 3l vconnected by a link 32 at its lower end with a spool 33 of the valve I'5. spaced-apart pins 34 and 35 on the upper end of the lever 3|- are alternately pressable upon by profiles 36 Vand 31 of a cam head 38 on the lower end of the lever 21. A third prole, 39, of the cam 38 is alternately cooperable with the pins 34 and 35 for retaining the lever 3I in respective pivoted operating positions.

Control valve spool 33 is illustrated in Fig. 1 in position R, which is its rightmost limit of movement. Pivoting of the lever 21 counterclockwise from the Fig. 1 position for carrying the cam profile 31 against the pin 35 will return the valve spool to the neutral position N, at which time the pins 34 and 35 will be against their respective cam profiles 38 and 31. Movement of the valve spool t its leftmost position indicated by the letter L is accomplished by further counterclo'ckwise pivoting of the lever 21 for causing the cam prole 31 to press against the pin 35 and thereby pivot the lever 3| clockwise. When the valve spool 33 is in position L, the lever 3I will be in the position illustrated by dotted lines. Continued pivoting of the lever 21 to its dotted line position can occur after the lower end of the cam profile 31 clears the pin 35 and as the cam profile 39 slides along the pin 35 in a relation with respect thereto as illustrated with regard to the pin 34 in Fig. 1.

When the spool valve 33 is in the neutral position N, the ram unit I2 will be hydraulically locked against operation. Movement of the ram plunger or piston in one direction is accomplished by setting the spool valve in the position R, whereas movement of the piston in the opposite direction can be accomplished by setting the valve spool in the position L. This will be fully explained presently after an explanation of the parts for conducting iluid to the valvel from the pump (not shown).

When the casing II is inserted upwardly into the body of the tractor, a recess 4I in a side of the casing II is brought into axial registry with a hole 42 in the tractor body wall I3. Thereafter a tubular coupling member 43 having a head 44 upon its outer end is inserted into the tractor wall opening 42 for placing the interior of this tubular member 43 in communication with the recess 4I. A tubular bolt 45 is inserted through the head 44 and the bore of the tubular member 43 and rotated into threaded engagement with a threaded countersink portion 46 of the bore 4I. The hollow bolt 45 serves as a means for attaching the tubular member 43 and also the casing II and the tractor side wall I3 in assembly. Additionally, the hollow bolt 45 provides communication between a high pressure passage 41 in a manifold cap 48 and a high pressure channel 49 in a side wall of the casing Il. A low pressure passage I inthe manifold cap 48 communicates through the tubular member 43 with a low pressure passage '52 in the casing II. Cap screws 53 secure the manifold cap 48 upon the head 44 of the tubular member 43.

Passage 52 extends from a lower end 524, Fig. 1, near the bottom of the reservoir casing II upwardly along the front wall of such casing and thence diagonally upwardly into communication with the tubular member 43, Figs. 1 and 1. Fluid is thus drawn upwardly from the bottom of the reservoir casing into the tubular member 43, thence into the manifold passage 5I and outwardly through `an exhaust conduit 54 to the inlet side of the pump (not shown). Fluid is deliveredfrom the pump through a conduit 55 into the manifold passage l41 and thence through the'hollow bolt 45, and passage 49, which also leads down the front wall of the reservoir casing 4 II as shown in Figs. 1 and 5. The bottom wall 56 of the casing II contains a hole 51 through which the lower end of the passage 49 communicates with a channel 58, Figs. 1 and 5, formed in the upper face of the plate I4 and closed by the plate 58. Channel 58 is also shown in Fig. 6 where it leads to a pressure controlling unit 59.

This pressure controlling unit 59, as shown in Fig. 5, lays between the control valve units I5 and I5 for causing fluid to be delivered under pressure to either or both. Unit I5 is associated with the control mechanism and ram shown in Fig. l, whereas the unit I5EL is for similar association with another identical control mechanism and ram. With continued reference to Figs. 5 and 6, the pressure controlling unit will be seen to comprise an upper plate 6I, an intermediate plate 62', and bores and passages within the plates 56 and I4. Said plates are held in assembly by cap lscrews 63. While each of the valves I5 and |54 is in neutral, fluid delivered to the device 59 through the passage4 58 and entering a passage 64 past a loosely fitting plunger 65 is trapped to preclude escapement thereof through a hole 63 and a transverse passage 81, Figs. 5 and 6, which leads to each of the control valves. The trapped iiuid in the passage 84 exerts its pre-ssure upon the upper side of a piston B8 reciprocable in a bore 69. TheV pressure of this uid will be equal to the pressure of the uid in the passage 53 and since the area of the piston 68 exceeds the area of that portion of a by-pass valve ball 1I covering a seat 'I2 therefor, the force upon the piston will prevail and said ball will be held unseated against the force of a spring 13. Fluid will therefore escape at low pressure past the unseated ball 1I and through an exhaust passage 14 into the reservoir casing II. A safety valve 15 is normally closed but is openable against the force of a spring 16 to permit the escape of fluid into the reservoir casing II through an exhaust passage 11 only during an abnormal pressure in the passage 58. A transverse pressure delivery passage 18, Fig. 5, intersects the passage 58 for directing liquid therefrom to each of the valves-I 5 and |54.

Referring now to the valve I5, it has a ca-sing 19 containing a cylindrical bore 8| into which there is pressed a sleeve 82 having five axially spa-ced circumferential grooves, each containing a rubber sealing annulus 83. These sealing rings 83 establish sealed connections between the sleeve 82 and the valve casing 'I9 while permitting slight transverse movement of the sleeve within its casing as an expedient for increasing manufacturing tolerances and avoiding distortion of the inner periphery of the sleeve when the casing 19 is bolted in place. There are four annular grooves 84, 85, 86, and S'I circumscribing the sleeve 82. These grooves communicate with the interior of the sleeve 82 by means of circumferentially spaced ports 88, 89, 9|, and 92. The ends of the bore in the valve sleeve 82 communi-cate with the reservoir casing II. Therev are lands 93, 94, and 95 on the valve spool 33 which control the opened or closed or intercommunicative condition of the various ports 88, 89, 9|, and 92.

Annular groove 84 of the valve sleeve 82 communicates with one end of the lateral passage B1 through a vertical passage 96. Annular passage 85 communicates with an L-shaped passage 91 through a pas-sage 98. Annular passage 85 communicates with the transverse fluid delivery passage 18 through a vertical passage 99. Annular passage 81 communicates with an L-shaped passage through a vertical passage |02. Corresponding elements are provided with respect to the valve unit |53, and those shown in Fig. are designated by the same respective reference characters as those described above for the valve I5, with the addition of the small letter a.

The horizontal part of the L-shaped passage 91 communicates with the hose |6. The other end of this hose I 6, as illustrated in Figs. 1 and 3,

communicates with one end of a passage |05 which leads `from the cylinder head, |06 through a tube |08 to the opposite cylinder head |01 and thence into the piston rod end of the cylinder. L-shaped channel |0|, Figl, communicates with one end of the hose |1, of which the other end communicates through a channel |09 of the cylinder head |86 with the end of the cylinder carrying the head |86.

A third hose, ||0, extends between the ram |2 and the reservoir casing This hose is a control hose and communicates with a recess in the ram cylinder head |06 through a bore 2. The opposite end of the control hose I0 communicates with an L-shaped bore ||3 in the casing plate |4 and thence with a channel ||4 in the open face of said plate. A flexible hose ||5, which may be considered a section of the control hose ||0, is communicatively connected between the channel I4 and an axial bore 6 in the piston rod 24 of the hydraulic device 2| and hence with the cylinder 22.

The ram piston ||1 contains a, valve receiving bore |8 having a lateral portion 9 which communicates with a pump chamber |2| formed by a bore in the piston rod |22. |23 in an end of the bore H8 serves as a reaction member for a -compression spring |24 which urges the ball |25 of a by-pass valve upon a seat |26 for closing this valve. Normally the by-pass |25|26 is closed, but when the piston moves to its limit of movement toward the cylinder head |06, a valve operating stem |21 abuts against a plate |28 and is moved endwise relatively to the cylinder for unseating the ball |25 and thereby opening such by-pass valve. Communication is thereby established between the piston rod end of the cylinder and the bore |2|, but not between the two ends of the cylinder. A plunger for the bore comprises a tube 29 having a headed end |30 secured in the cylinder head recess by the plate |28 and screws 3|. The tubular rod |22 and the tube |29 constitute a pulsator chamber |2|-|29. A hole |32 in the piston ||1 has a Sealing sliding fit with the exterior of the tube |29 whereas there is clearance between the tube and the pump chamber |2| in the piston rod.

When the ram piston l1 is at rest, the pulsator chamber |22- |29 will likewise be at rest so that iiuid within a pulsator chamber formed by the cylinder 22 and piston 23, Fig. l, will be of fixed Volume and held under compression by a contraction spring |36. This spring |36 is connected with intermediate portions of members |31 and |38 which are pivotally connected together by a pin |39 at one end and which have their opposite ends pivotally connected respectively with the piston rod 24 and the cylinder 22 at 25 and 26. This compressive action of the spring |36 upon the fluid in the hydraulic device 2| rigidies the valve manipulating means so that the manually settable control member I8 can be rocked in either direction for transmitting operating force in corresponding directions to the valve spool 33. When the fluid containing chamber of the hydraulic device 2| is fully ex- An apertured plug tended as illustrated in Fig. 2, an abutment plate |4| mounted on the piston rod end of the cylinder 22 abuts against a valve stem |43 for unseating a ball |44 of a by-pass valve |45 so iiuid can escape from the chamber in cylinder 22 through i a passage |46. A leaf spring |41 normally holds the valve ball |44 seated. The linkage chamber 22-23 and the ram operated chamber |22-|29 together with the conduit structure including the hose sections |0'-| I5 providing communication between such chambers constitute a pulsator Operation of the apparatus First, it will be assumed that the entire hydraulic system of the apparatus is completely filled with fluid and that the manual control member I8 has just been moved to the full line position shown in Fig. 1 for causing movement control member I8 into the full line position of Fig. 1, the hydraulic linkage I9 which is then rigidified by the action of the spring |36 retainling the fluid in the chamber thereof under compression, will be effective for pivoting the lever 21 clockwise about its fixed pivot 28.

pins 34 and 35 had occupied similar positions along the proles 36 and 31 of the cam head 38 and thus caused the valve spool 33 to be in the neutral position N. As the control member I8 was swung counterclockwise andthereby caused clockwise movement of the lever 21, the cam prole 36 pressed against the pin 34 for swinging the lever 3| counterclockwise in moving the valve spool 33 into the operative position R. Continued movement of the control member |23l to the full line position was possible after the valve had been moved to the position R because of.

and 5, and passage 58-Figs. 1, 5. and 6, to the`V pressure controlling Valve 59. While thevalve spool 33 was in the neutral position N, a land 93 thereof was in registry with the valve portsV 88 and thereby prevented escape of fluid through the passage 61, Figs. l, 5, and 6, from the passage 64 in the pressure control valve 59. Consequently, fluid from the passage 58 flowing past the circumferentially ribbed member 65 into the passage 64 built up pressure above the piston 68 for holding the by-pass valve ball 1| unseated so that the fluid entering the passage 58 from the pump could escape at low pressure through the by-pass passage 14 in Figs. 5 and 6.

Upon the movement of the valve spool 33 to the position R, however, the spool land 33 wasl displaced from the ports 88 so that fluid could escape through these ports into the casing reservoir from the passage 64-Fig. 6, at a greater rate than the fluid could be replaced in said passage 64 through the interstice about the circularly ribbed member 65. The pressure is thereby diminished above the valve piston 68-Fig. 6, so that the spring 13 andthe pressure iluid in the passage 58 is effective for closing the valve ,1 |-12 so that pressure builds up in the passage 58 and the transverse passage 18, Figs.` 1 and ,5. 1;

Prior to v this pivotal movement of the lever 21, the twovk In Fig. 1, it can Vbe seenthat'the fluid of increased .pressure within the passage 18 then ows upwardly through passage 99 and through the valve ports 9|, outwardly through the valve ports 92 into the passage |92, thence through L-shaped passage lill, conduit l1, and passage |09 in the ram cylinder head |99, Fig. 3, into the right end of the ram cylinder for forcing the piston toward the piston rodV end of the cylinder. Asthe piston is moved toward the piston ro'd end of the Yram cylnderfluid is expelled from the cylinder through the passage |95, conduit I6, L-shaped passage 9l, Fig. 1, valve ports `89, and an L-shaped passage in the left end of the spool 33 to the casing reservoir As the ram piston moves to the left, the pulsator chamber |22|29 increases in volume and thereby adapts such chamber to receive fluid expelled from the chamber of the hydraulic linkage by the force of the spring |36. rlhe rate at which the fluid is transferred from the hydraulic linkage -chamber into the ram operated chamber |22|29 is in accordance with the rate of expansion of the chamber P22-|29. Fluid reaches the expanding chamber |22|29 through piston rod bore '||6, Fig. 1, control hose section H5, channels ||4 and ||3 in the casing plate hl, control hose section lill, cylinder head passage H2,

Fig. 3, and the bore in the hollow rod |29.

The transfer of fluid from the hydraulic linkage chamber to the ram operated chamber |22|29 is in accordance with the amount of movement of the ram piston i il, and as the linkage chamber contracts under the influence of 'the spring |36, the lever 2l is pivoted counterclockwise and eventually pivots the lever 3| clockwise .for returning the valve spool 33 to neutral when the ram piston has moved an amount corresponding to the amount of the initial setting of the manually settable control member IB.

When the control member |8 is moved oppositely, toward the dotted line position, after the contraction of the chamberaof the hydraulic linkage has reestablished the neutral position of the valve spool 33, this clockwise swinging of the control member will be operable through the hydraulic'linkage for moving the valve spool from the neutral to the position L. This displacement Vof the valve spool will place the annular space between the lands 93 and 94 in reglistery with the valve ports 88 so that fluid can escape from the pressure control device 59 through Vthese ports 88 and the L-shaped spool channel |5| into the casing reservoir As a consequence, the pressure controlling device 59 will cause its by-pass valve 'H--12 to close and increase the pressure in the channels 58 and 18,- Figs. 1, 5, and 6. At the same time, the ports 9|, through which high-pressure fluid is introduced into the valve. l5, will be communicable through the space between the spool lands 94 and 95 with the ports 39 so that the high pressure fluid is conducted outwardly through ports 89 into the L-shaped channel 91 and therefore introduced into the piston rod end of the ram cylinder for forcing the piston |I'| `to the right. Concurrently fluid is 'exhaused vfrom the right end of the ram cylinder through the hose L-shaped passage IBI, Fig. .1, and valve ports 92, into the casing reservoir since the valve spool land 95 will then be to the left of the ports 92, Fig. -1.

-As the ram 4piston is thus moved to 4the right, Fig. -3, the `fluid capacity of the fram opthrough the control hosev H0, the passages H3., and ||l|` in the casing plate I4, and the, control hose section H9 and piston rod bore ||6 into the hydraulic linkage chamber for extending the hydraulic linkage. This extension of the. hydraulic linkage causes the lever 2l to pivot clockwise whereby the lever 3| is pivoted counter-V clockwise for returning the valve spool from the position L to the neutral position N. When this occurs,4 coincidentally with the ram piston. movingV an amount correlated with the amount of initial clockwise displacement of the control been conned to the valve i5, the ram I2 associated therewith and the particular controls for said valve and ram, identical operation-occurs for the valve |521, its associated ram and the controls for such valve and ram. The setting `of either of the valves from its neutral position will permit the escape of iluid from the pressure controlling device passage 64 for creatingthe high pressure condition of the fluid for operating the rams, and the iiuid is prevented from escaping from the chamber 99 of the pressure controlling device 59 when both of the valves l5 and I5a are set 'm neutral, whereby the low pressure by-pass condition of the device 59 will prevail.

rWhen the apparatus has been initially assembled and not yet filled with fluid, the spring |39v will hold the chamber of the hydraulic linkage in its fully contracted position, that isthe piston 23, Fig. 1, will be forced all of the way into the cylinder 22. rIhe control member I8 will be set to its oscillative limitv shown by the dotted lines in Fig. 1 and this will cause the lever 21 to be rotated its maximum amount counter-- clockwise whereby the valve l5 will be set in operating position L. Therefore, when the main pump is started, fluid therefrom enteringk the passage 58, Figs. 1, 5, and 6, will be effective for closing the by-pass valve li-TZ. Since the control ports 88 of the control valve l5 will then be in registery with the space between the lands 93 and 9d and communicative with the reservoir through the L-shaped passage 5|, pressure can-` not build up in the pressure control device passageV $9, Fig. 6, and the by-pass valve 1|-|2 will` be closed. Fluid under pressure will therefore flow from the passage 58 and through the rlateral i9, valve ports 9| and 89, then between the-spool lands 94 and 95, passage 91, conduit I6, and ram passage |95 to the piston rodA end of the. ram cylinder. At this time there will --be some air within the various passages and within the ram cylinder and this introduction of iluid into the.

control hose section H5, the bore VVin the piston,

rod 24, and into the cylinder 22 for expanding the hydraulic linkage.

l the pump into the control hose section III) and nally into the fluid chamber of the hydraulic valve operating linkage. The hydraulic device 2| has a limited stroke, however. so that full extension thereof while the control member I8 is set in the dotted line position of Fig. 1, which corresponds to the position shown in Fig. 2, the full expansion of the linkage will be insufficient to return the valve from the operating position L to the neutral position N. So long, therefore, as the control member is allowed to be set in the Fig. 2 position, uid introduced into the piston rod end of the ram cylinder will ow through the by-pass valve IE-|26, through the pump |22-I29, the control hose sections I I0 and I I5, and into the fluid chamber of the hydraulic linkage. When the fluid chamber of the hydraulic linkage is fully extended as illustrated in Fig. 2, the valve stem |43 engages the abutment plate |4| and opens the bv-pass valve |45 against'the force of the spring |41 so that the air and fluid can escape into the reservoir. The apparatus is allowed to operate under this condition sufficiently long for the fluid to wash virtually all of the air from the fluid containing passages. This is a convenient expedient for completely filling the fluid containing passages of the system with the non-compressible liquid. It will be seen that uid from the normal power hydraulic circuit of the system is admitted to the normal control hydraulic circuit through the valve |25-I26 in the ram piston and that the by-pass valve in Fig. 1 is adapted to permit the l escape of the uid from the control circuit.

When the system has been filled with oil which has displaced the air, the manually settable control member |8 can be swung counterclockwise from the limit of its clockwise movement sufciently to operate the hydraulic control linkage for setting the valve spool 33 in the neutral position. 'I'he control member I8 and the ram piston I II will then be predeterminedly phased. Additional movement of the control member I8 in the counterclockwise direction will cause the valve spool 33 to be set into the operating position R so that uid from the main pump will be introduced into the right end of the ram cylinder as explained hereinabove for causing movement of the ram piston toward the piston rod end of such cylinder. A few, strokes of the control member I8 swinging the same first clockwise and then counterclockwise and thereby causing pumping action of the ram will duicklv cause all of the air'in the right hand end of the ram cylinder to be displaced into the reservoir |I, where it escapes from above the fluid level.

Normally, the control member I8 will b e manipulated within a range of movement between the full line position shown in Fig. 1 and a position -just short of the dotted line position of Fig. 1. Within this normal range of movement of the movementof the control member. During this normalpperation of 'i the apparatus, neither of the by-pass valves I25--I26 in the ram piston nor |45 in the hydraulic linkage piston will be opened. If, however, leakage of fluid should occur from the hydraulic control system including the ram operated pulsator chamber |22-I29 and the pulsator chamber 22-23, incorporated into the hydraulic control linkage I9, Fig. 1, so that the ram piston operates somewhat out of phase with respect to the phase relation initially established by moving the control memberv I8 into the dotted line position in Fig. 1, the initial predetermined phase relation can be immediately reestablished simply by placing the control member into the dotted line position so that the ram piston II'I will be forced into the Fig. 3 position. Fluid will then be forced from the piston rod end of the cylinder past the open by-pass valve |25-I26 into the pulsator chamber I22-I29 and thereby force suiiicient iiuid into the hydraulic linkage pulsator.chamber 22-23 for replenishing the fluid lost by leakage and fully expanding the hydraulic linkage.

It is also contemplated that out of phase relation of the manually settable member I8 and the ram piston |I may occur by leakage of uid past the ram piston II'I from the right end of the cylinder to the left end thereof. Should this occur, it would create the out of phase relation which would cause the piston II to lag behind the position it should be relatively to the control lever I8 when this lever is moved toward the dotted line position in Fig. 1 for causing the piston to move toward the right end of the ram cylinder. When this condition prevails, it can be likewise corrected by simply setting the control member |8 into the dotted line position. Thereafter when the ram piston operates the control system pulsator chamber I22-'"|29 for fully extending the hydraulically controlled linkage before the ram piston reaches the right end of its cylinder, the fully extended hydraulic linkage will be incapable of returning the control valve spool 33 to the neutral position from 'the L operating position, wherefore fluid will continue to be delivered into the piston rod end of the ram cylinder and eventually cause the piston to reach the right end of the cylinder in the predetermined phase relation with respect to the control member I8. As long as the control member I8 remains in the extreme dotted' line position fluid delivered by the main pump will 'iiow successively through the ram piston by-pass Valve I 25-I26 and the hydraulic linkage bypass valve |45 as explained hereinabove in the explanation of rephasing when the control member i8 and the ram piston were out of phase'in the opposite direction. Theiiow of uid'through the hydraulic linkage chamber is stopped when the control member is moved far enough from the extreme dotted line position to operate the hydraulic linkage for returning the valve. spool 33 to neutral. The rephased condition of the manually settable control member I8 and the ram piston will prevail until there has been a cumulative leakage past the ram piston or from the control hydraulic circuit including the pulsator chamber |22-I29 and 22---23.v FAs eX- plained above, however, it is a simple matter to correct an out of phase relationv in eitherdirecibot'iimen't. of l theA invention with the. View of clearly and concisely illustrating the same, we clairnzV Y 1. Ina control for a two-way hydraulic ram y Q having Aa cylinder and a piston, a source of pressure uid for the operation of said ram, a control valve from which said ram is remotely disposed, said valve having communicative connections with the source and with the ram and be- A ing settable in opposite directions from a neutral to establish said communicative connections for operation of theram inrespectively opposite divrections,.ahydraulic assemblage connected with `thevalve `and .manually operable in opposite directionsfor selective setting of the same, the as- .semblagey being hydraulically operable in either kof opposite directions for returning the valve toward neutral according to whether fluid is received-by `or expelled from such assemblage, a Y

hydraulic pulsator including intercommunicative expansible and contractible chambers of which one is' incorporated into said assemblage as a hydraulic receiver and operator thereof, the other of such chambers being associated with said ram in a manner to be expanded or contracted thereby, said ram-associated chamber being contracted by the ram to pump fluid from such chamber into the assemblage-incorporated chamber Vas'the ram piston approaches a limit toward one end of the cylinder and to accomi modate uid expelled from the assemblage pursuant to reverse movement of the piston, said Vvalve being returned toward neutral by operation-of the' assemblage while receiving fluid and stopping short of reaching neutral should there be Va deciency of uid in the pulsator wherefore the piston continues to said limit, and means Vincluding a by-pass valve operable substantially coincident with the piston reaching said limit Y to establish communication between the source and said pulsator to increase the quantity of fluid therein by the amount of such deciency.

2. The combination set forth in claim l, wherein there is a conduit providing the communication between the pulsator chambers, and wherein said by-pass valve is associated with the ram and is disposed to provide the communication between the source and assemblage-incorporated chamber by Way of said conduit.

3. The combination set forth in claim l,

wherein there is another by-pass valve associated Withsaid pulsator to open and facilitate discharge of the fluid from said source therefrom when the assemblage-incorporated chamber is ulIy'eXpanded.

lished through the conduit means from the source to one end of the ram cylinder and communication is also established between the other end of the cylinder and a place of exhaust; a hydraulic pulsator comprising intercommunicative expansible and contractible chambers of which one is .operated by the ram to expel fluid .as the ram pisf .tonis moved toward said otherend of the cylinder: valve operating means including a member 'manually settable Within a range, an extendible Vpulsator comprising l2 and contractible hydraulic linkage operably connected between said member and the valve, said hydraulic linkage incorporating the other expansible and contractible chamber which when varied in expansion causes variation in the degree of extension of said linkage, spring means for retaining the fluid in said linkage chamber under compression while biasing the linkage toward a variation in length oppositely to the variation caused by fluid entering the linkage chamber from the other chamber of the pulsator, and a bypass valve opened to facilitate discharge of fluid from said linkage chamber substantially coincident with said chamber being fully expanded; a second by-pass valve openable to establish communication between the one end of the ram cylinder and said other chamber substantially coincident with Ythe piston reaching ga, limit toward said other end of the cylinder; said linkage being capable of transmitting setting force from the manually settable member to the control valve to place it in said operating position when said member is moved Vtoward a limit of its setting range, said linkage being operable by the ensuing delivery of fluid from the said other chamber into said linkage chamber for returning the `valve toward neutral, and the linkage being so limited in operation that when the control member is Set at said limit of its setting range full expansion of the chamber causes insufficient linkage operation to completely return the valve to neutral, whereby if the control member and piston are so dephased that the linkage chamber becomes fully expanded before the piston reaches its limit the failure of the fully expanded chamber to have returned the control Valve to neutral will cause continued fluid delivery from the source into lthe one end of the cylinder to complete movement of the piston to its limit, and whereby if the control member and piston are so dephased that the piston reaches its limit prior to full expansion of the linkagelchamber the second by-pass Valve will be opened to admit fluid from the source to supply the linkage chamber deciency incident to fully expanding the same. Y

5. In a control for a hydraulic motor; a source oflpressure fluid for said moto-r: a valve manipulatable from a neutral positionV wherein it is effective to communicatively isolate the motor from said source to an operating position establishing communication betweenthe source and motor to cause motor operation; a hydraulic inter-communicative expansibleand contractible chambers of which one is operated by said motor inya manner causing fluid displacement in an amount correlated with the degree of operation of the motor; and valve manipulating means including a manually settable member, an extendible and contractible hydraulic linkage operably connected between said member and the valve, said hydraulic linkage including the other pulsator chamber which when varied in volume causes corresponding variation in the degree of extension of said linkage, and means for compressing fluid in said linkage chamber whilebiasing the linkage toward a variation in length oppositely to that variation caused by fluid pumped into said chamber from the ramoperated chamber, said linkage being capable of transmitting manipulating force from the manually settable position tothe valve to place it in the operating position, and the linkage being operable bythe ensuing exchange of fluid between the chambers VtoY return the valve to `neutral pursuant to 'operation of vthe motor van amount "criated with the distance the settabie niember is set.

6. In a control for a two-way hydraulic ram; a source of pressure fluid for said ram; a valve with respect to which said ram is remotely disposed; conduit means communicative between said valve and said source; exible hose means communicative between said valve and said ram; said valve being manipulatable from a neutral position wherein it is eiective to communicatively isolate the motor from said source to alternative operating positions disposed oppositely from the neutral to establish communication through said conduit means and said hose means between said source and respective opposite ends of the ram for causing it to be operated in selectively opposite directions; a hydraulic pulsator comprising inter-communicative expansible and contractible chambers of which one is operated by said ram in a manner causing iluid displacement in direction and amount correlated with the direction and amount of operation of the ram; and valve manipulating means including a manually settable member, and an extendible and contractible hydraulic linkage operably connected between said member and the valve, said hydraulic linkage including the other pulsator chamber which when Varied in volume causes corresponding variation in the degree of extension of said linkage; a control hose communicating between said chambersr to provide for their inter-communication, and means for compressing fluid in said linkage chamber while biasing the linkage toward a variation in length opposite to that Variation caused by fluid pumped through the control hose into such linkage chamber, said linkage being capable of transmitting manipulatingbfcrce from the manually settable member to the valve for setting the latter in either of said opposite positions from neutral, and said linkage being operable by ensuing transfer of fluid between the chambers to return the valve to neutral pursuant to operation of the ram in direction and amount i correlated with the direction and distance of setting of the settable member.

7. In a control for a hydraulic ram having a cylinder and a piston; a source of pressure fluid for said ram; a valve; Iconduit means connecting the valve and source and connecting respective ends of the ram cylinder with the valve; said Valve being manipulata-ble from a neutral position wherein communication between the source and the ram through said conduit means is precluded to a position whereby communication is established through the conduit means from the source to one end of the ram cylinder and communication established between the other end of the ram cylinder and a place of exhaust; a hydraulic pulsator comprising intercommunicative expansible and contractible chambers of which one is operated by the ram to expel fluid as the ram piston is moved toward said other end of the cylinder; and valve operating means including a Imanually settable member, an entendible and contractible hydraulic linkage operably connected between said member and the valve, said hydraulic linkage including the other of said pulsator chambers which when varied in volume caus-es corresponding variation in the degree of exten-sion of said linkage, means for compressing fluid in said chamber while biasing the linkage toward a variation in length oppositely to that variation caused by fluid entering the linkage chamber from the ram-operated chamber, and a by-pass 14 valve opened to facilitate discharge of duid from said linkage chamber substantially `coincidentally with said chamber being fully expanded; a second by-pass valve opena'ble to establish communication between the one end of the ram and said pulsator substantially coincident with the rain piston reaching a limit toward said other end of the cylinder; said linkage being capable of transmitting manipulating force from theL manually settable member to the valve to place it in saidA operating position when the settable member is moved toward a limit of its setting rang-e, said linkage being operable by the ensuing delivery or" iiuid from the ram-operated chamber into said linkage chamber and while reacting against the set settable member for returning the valve toward the neutral position but said linkage chamber becoming fully expanded to terminate such operation of the linkage and avoid return of the valve to neutral when said manually s-ettable member has been set to a terminus of its setting range, whereby, after the ram piston reaches said limit toward the other end of the cylinder into a predetermined phased relation with the control member, fluid from the source can escape past the second by-pass valve into said linkage chamber, and outwardly of the linkage chamber through the first by-pass valve.

8. In a `control for a two-way hydraulic ram having a cylinder and a piston; a source of pressure duid for said ram; a valve communicatively connected with said sourceY and with opposite ends of the ram cylinder; said valve being settable in opposite directions from a neutral setting wherein it is ineffective for establishing communication between the source and ether end of the cylinder, said valve being operable when in one of said positions to establish communication between the source and one end of the cylinder while establishing communication between the other end of the cylinder and a place of exhaust and being operable when in the other position from neutral for establishing communication lbetween the source and said other end of the cylinder while establishing communication between the one end of the cylinder and said place of exhaust; a hydraulic pulsator comprising inter-communicative expansible and contractible chambers of which one is operated by said ram for discharging fluid when the ram piston is .moved toward said other end of the cylinder; and valve setting means comprising a settable member variously settable within a range of movement thereof, a hydraulic linkage connected between said member and the valve and operable to transmit force from said member for setting the valve in the one position when the member is set toward one limit of its range and for setting the valve in the other position when the member is moved toward the other limit of its range, said hydraulic linkage including the other pulsator chamber which is an expansi'ble chamber for causing said linkage to move the valve from said one position toward the neutral but having insufcient expansion for completely resetting the valve to neutral when the control member has been set to the limit of its range, and a by-pass valve associated with said linkage chamber and operable to discharge -fluid therefrom lcoincident with it becoming substantially fully expanded; a conduit communicative between said chambers to provide the inter-communication therebetween and thus ydeliver into the linkage chamber the uld discharged from-'the Yram-cperated chamber .thereone end of the cylinder into said linkage chamber Iby way of said conduit coincidentally with the piston reaching the other end of the cylinder.

9. The combination set forth in claim 8, wherein the ram-operated chamber contains a port through which iiuid is admitted from the conduit when the ram piston is moved toward the one end of the cylinder and through which port fluid is discharged into the conduit when the ram piston is moved toward the other end of the cylinder, and wherein the chamber is arranged in series with the second by-pass valve and said conduit.

10. The combination set forth in claim 8, wherein the ram-operated chamber comprises an open-ended axial bore communicating through the ram piston and a hollow rod anchored in said other end of the ram cylinder and projecting into said pump chamber, said conduit being communicative with said chamber through said hollow rod, and said second by-pass valve being within the ram piston for providing communication between the one end of the ram cylinder and said chamber when such valve is open.

11. The combination set forth in claim 8, wherein a piston rod is connected with the ram piston and projects therefrom through a gland in the one end of the ram cylinder, wherein said ram-operated chamber comprises an axial bore extending from within said piston rod through said piston and a hollow rod anchored in said other end of the ram cylinder and projecting into said chamber, the exterior periphery of said hollow rod being in sealed sliding relation with a portion of the bore in said piston and being in radially spaced relation with respect to that portion of the bore within the piston rod, a bore in said piston communicating between the one end of the ram cylinder and the piston rod bore,

. and said second by-pass valve being disposed within the last-named bore.

12. In a two-way hydraulic ram and a control for the admittance of operating pressure fluid therein, a ram cylinder, a piston reciprocable in said cylinder, a piston rod extending through one end of the cylinder, means for the selective admittance of fluid intov opposite ends of saidvcylinder, a pulsator comprising a chamber in ,the form'of an axial bore extending through said piston from the end thereofdisposed toward the other end of-said cylinder and into the piston rod, a portion of said bore within the piston 4being of smaller diameter than the portion Within the piston rod, a hollow rod anchored in said other end ofthe cylinder and projecting into the pump chamber through said smaller diameter portion of the bore in the piston, a control channel in said other end of the cylinder communicative with the interior Vof said hollow rod, a valvereceiving bore in said piston and communicative between the one end of the cylinder and said pulsator chamber, a normallyV closed by-,pass valve within said valve-receiving bore, and means for opening said by-pass valve coincident with the approach of said piston toward said other end of the cylinder.

13. The combination set forth in claim l8, wherein the extendible and contractible linkage chamber is in the form of arcylnder having a piston therein, and wherein said linkage in addition to including said cylinder and piston includes a pair of members pivotally connected together at one end and having their opposite ends respectively pivotally connected with said piston and said cylinder, and a spring connected between said members and imparting force Ythereto tending to move the piston in the direction to diminish the content of the cylinder bore.

JOHN R. IORELIND. CARL W. MOTT.

REFERENCESV CITED Y The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 897,907 Lang Sept. 8, 1908 2,010,645 Roberts Aug. 6, 1935 2,192,963 Davis Mar. 12, 1940 2,292,916 Wheelon Aug, 11, 1942 2,385,942 Rockwell Oct. 2, 1945 FOREIGN PATENTS ANumber Country Date '702,983 Germany Feb. 25, 1941 558,460 Great Britain Jan. 6, 1944 

